The present invention relates generally to power-saving in storage systems and, more particularly, to methods and apparatus to provision a data storage configuration with consideration of the power control schedule of storage subsystems.
Recently power consumption efficiency in information systems is gaining attention as an important issue and many enterprise organizations are committed to improving their information systems to conserve energy. Under current solutions, users can save electric power consumption by switching on and off the power supply of the entire storage apparatus or a part of the storage apparatus in their operation. For example, U.S. Patent Application Publication No. 20070079156 provides a method to control the power supply on a hard disk group basis, and to determine the time to turn on or off the hard disks based on collected system running information. Applying current solutions, it is possible to reduce power consumption by supplying electric power only when it is necessary and stopping it when it is unnecessary. For instance, users can turn on the power of the storage device that stores backup data only during the time when the backup process is running, and turn off the power after backup is done because the backup data storage is normally accessed only during a backup process except restoration.
The application of current solutions, however, gives rise to a situation in which a single information system includes both storage apparatus that are always turned on and storage apparatus that are regularly turned off. This mixture of different data storage apparatus makes it difficult for users to provision a new backup configuration. If they do not locate a backup data volume properly, the new backup set cannot take advantage of the power-saving storage system. For example, if they locate a backup volume in permanently power-on storage, the backup volume keeps consuming electric power even though it is not necessary until the backup process starts. On the other hand, if they locate a backup volume in a regularly turned-off storage, they need to be sure the scheduled backup time is within the available time of the power-saving storage.